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Diffstat (limited to 'gfx/skia/skia/include/core/SkFontMetrics.h')
| -rw-r--r-- | gfx/skia/skia/include/core/SkFontMetrics.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/gfx/skia/skia/include/core/SkFontMetrics.h b/gfx/skia/skia/include/core/SkFontMetrics.h new file mode 100644 index 0000000000..f496039311 --- /dev/null +++ b/gfx/skia/skia/include/core/SkFontMetrics.h @@ -0,0 +1,139 @@ +/* + * Copyright 2018 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkFontMetrics_DEFINED +#define SkFontMetrics_DEFINED + +#include "include/core/SkScalar.h" +#include "include/private/base/SkTo.h" + +/** \class SkFontMetrics + The metrics of an SkFont. + The metric values are consistent with the Skia y-down coordinate system. + */ +struct SK_API SkFontMetrics { + bool operator==(const SkFontMetrics& that) { + return + this->fFlags == that.fFlags && + this->fTop == that.fTop && + this->fAscent == that.fAscent && + this->fDescent == that.fDescent && + this->fBottom == that.fBottom && + this->fLeading == that.fLeading && + this->fAvgCharWidth == that.fAvgCharWidth && + this->fMaxCharWidth == that.fMaxCharWidth && + this->fXMin == that.fXMin && + this->fXMax == that.fXMax && + this->fXHeight == that.fXHeight && + this->fCapHeight == that.fCapHeight && + this->fUnderlineThickness == that.fUnderlineThickness && + this->fUnderlinePosition == that.fUnderlinePosition && + this->fStrikeoutThickness == that.fStrikeoutThickness && + this->fStrikeoutPosition == that.fStrikeoutPosition; + } + + /** \enum FontMetricsFlags + FontMetricsFlags indicate when certain metrics are valid; + the underline or strikeout metrics may be valid and zero. + Fonts with embedded bitmaps may not have valid underline or strikeout metrics. + */ + enum FontMetricsFlags { + kUnderlineThicknessIsValid_Flag = 1 << 0, //!< set if fUnderlineThickness is valid + kUnderlinePositionIsValid_Flag = 1 << 1, //!< set if fUnderlinePosition is valid + kStrikeoutThicknessIsValid_Flag = 1 << 2, //!< set if fStrikeoutThickness is valid + kStrikeoutPositionIsValid_Flag = 1 << 3, //!< set if fStrikeoutPosition is valid + kBoundsInvalid_Flag = 1 << 4, //!< set if fTop, fBottom, fXMin, fXMax invalid + }; + + uint32_t fFlags; //!< FontMetricsFlags indicating which metrics are valid + SkScalar fTop; //!< greatest extent above origin of any glyph bounding box, typically negative; deprecated with variable fonts + SkScalar fAscent; //!< distance to reserve above baseline, typically negative + SkScalar fDescent; //!< distance to reserve below baseline, typically positive + SkScalar fBottom; //!< greatest extent below origin of any glyph bounding box, typically positive; deprecated with variable fonts + SkScalar fLeading; //!< distance to add between lines, typically positive or zero + SkScalar fAvgCharWidth; //!< average character width, zero if unknown + SkScalar fMaxCharWidth; //!< maximum character width, zero if unknown + SkScalar fXMin; //!< greatest extent to left of origin of any glyph bounding box, typically negative; deprecated with variable fonts + SkScalar fXMax; //!< greatest extent to right of origin of any glyph bounding box, typically positive; deprecated with variable fonts + SkScalar fXHeight; //!< height of lower-case 'x', zero if unknown, typically negative + SkScalar fCapHeight; //!< height of an upper-case letter, zero if unknown, typically negative + SkScalar fUnderlineThickness; //!< underline thickness + SkScalar fUnderlinePosition; //!< distance from baseline to top of stroke, typically positive + SkScalar fStrikeoutThickness; //!< strikeout thickness + SkScalar fStrikeoutPosition; //!< distance from baseline to bottom of stroke, typically negative + + /** Returns true if SkFontMetrics has a valid underline thickness, and sets + thickness to that value. If the underline thickness is not valid, + return false, and ignore thickness. + + @param thickness storage for underline width + @return true if font specifies underline width + */ + bool hasUnderlineThickness(SkScalar* thickness) const { + if (SkToBool(fFlags & kUnderlineThicknessIsValid_Flag)) { + *thickness = fUnderlineThickness; + return true; + } + return false; + } + + /** Returns true if SkFontMetrics has a valid underline position, and sets + position to that value. If the underline position is not valid, + return false, and ignore position. + + @param position storage for underline position + @return true if font specifies underline position + */ + bool hasUnderlinePosition(SkScalar* position) const { + if (SkToBool(fFlags & kUnderlinePositionIsValid_Flag)) { + *position = fUnderlinePosition; + return true; + } + return false; + } + + /** Returns true if SkFontMetrics has a valid strikeout thickness, and sets + thickness to that value. If the underline thickness is not valid, + return false, and ignore thickness. + + @param thickness storage for strikeout width + @return true if font specifies strikeout width + */ + bool hasStrikeoutThickness(SkScalar* thickness) const { + if (SkToBool(fFlags & kStrikeoutThicknessIsValid_Flag)) { + *thickness = fStrikeoutThickness; + return true; + } + return false; + } + + /** Returns true if SkFontMetrics has a valid strikeout position, and sets + position to that value. If the underline position is not valid, + return false, and ignore position. + + @param position storage for strikeout position + @return true if font specifies strikeout position + */ + bool hasStrikeoutPosition(SkScalar* position) const { + if (SkToBool(fFlags & kStrikeoutPositionIsValid_Flag)) { + *position = fStrikeoutPosition; + return true; + } + return false; + } + + /** Returns true if SkFontMetrics has a valid fTop, fBottom, fXMin, and fXMax. + If the bounds are not valid, return false. + + @return true if font specifies maximum glyph bounds + */ + bool hasBounds() const { + return !SkToBool(fFlags & kBoundsInvalid_Flag); + } +}; + +#endif |